click on start then click on control panel
if you see a blue background with ten large icons you are in 'category view' so click on 'appearance and themes' the click on 'fonts' in the top left on that window - then click in 'file' 'install new font' then navigate to wherever you have downloaded them to and then make sure they are highlighted and click ok - and then they will install into your font folder
but if when you go to the control panel you see lots of icons and a white background, you are in 'classic view' and you can just click on 'fonts' then 'file' 'install new font' etc etc.
hope that helps